7/27/2019 Shure Notes Issue #30 - Revisiting the Classics
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"In other words,all cardioids
are not the same."
"Handling noise is one of the things thatyou really need to pay
attention to when
youre evaluating a microphone."
Tim, the SM57 and the SM58 have been the two best selling
microphones in the worldfor more than 40 years now. What has made
these two microphones so popular forso long?I think its a
combination of several things. The first would have to be the sound
quality for vocals
and instrument applications. The sound quality is excellent. The
industry has kind of revolvedaround the sound quality at this
point.
Well, lets dive into that a little deeper. When we talk about
sound quality, there area number of different aspects to microphone
design that contribute to sound quality.One of them is frequency
response. What is it about the frequency response of the 57and 58
that are particularly significant?The 58 is a vocal microphone and
it has a frequency range that is appropriate for the voice. It
rollsoff below 100 Hz or so, so you dont get a lot of low-end
rumble in the microphone. And it rolls offa li ttle bit above 15 or
16 kHz so you dont have to worry about high-frequency stuff outside
t he
range of the voice.
Within that range, the mic is relatively flat and has an
accurate
response except for a rising response between about 3kHz
and10kHz apresence rise which goes a long way toward improving
intelligibil ity of the human voice particularly in the presence
of alot of amplified instruments and other competing sound
sourcesin a li ve music application. Thats what gives the mics
that
clarity and punch that lets em cut through the mix. Most
sound
engineers find that they dont have to EQ them as much.
OK, what about pickup pattern? Thats another aspectof mic
performance that contributes to sound quality,indirectly in some
ways. The SM57 and SM58 are bothcardioid pattern microphones, which
is one of the mostpopular directional types. Tell us about the
polarpattern for each of these and how it affects the sound ofthe
microphone.The directional characteristic of these microphones is
the classiccardioid pattern. And one of the things that sets these
apart
from other cardioid types is that these have a very
uniformdirectional characteristic throughout their frequency
response.
The directional characteristics of low frequencies and high
frequencies are pretty similar. Becausetheyre smooth across that
range, theyve very good at rejecting feedback from nearby
monitors
and speakers.The directional uniformity not only gives great
control in terms of
feedback, pickup and ambient noise but it allows the
performer
to work the microphone a lit tle bi t off-axis without changing
thequality of his or her voice. In other words, all cardioids are
notthe same. Just because three microphones in the store all
have
a cardioid pattern doesnt mean that theyre going to sound
thesame and behave the same way on-axis and off-axis.
Another aspect of microphone design that a lot of people
overlook until its really toolate is the issue of the shock mount.
Whats the purpose of the shock mount? Howdoes it contribute to the
sound of the microphone?Directional microphones have mechanical
sensiti vity to impact noises and rubbing and so forth onthe case
of the microphone. If the microphone is going to be used handheld
or on a st and on a
stage where theres a lot o f vibration, you need to have some
mechanical isola tion built into themicrophone to prevent the
thumping and bumping noise from being picked up by the
microphone.
Although mics may be similar in their sound quality and
even their polar pattern, if youre going to use the thingin a li
ve application, the performance of the shock
mount in isolating the mechanical noise is very
apparent as soon as you pick up the mic or hold it.Handling
noise is one of the things that you really need
to pay attention to when youre evaluating a
microphone.
You can hear Tim and Chris perform a handling noise
test by listening to the Shure Cast SM57 & SM58:Inside the
Legends.
If youre going to spend $100 or more on amicrophone, one of the
big questions is howlong is it going to last? The durability of
the57 and 58 is legendary so the question is why do they hold up so
well?Durability or in t his case survivability of these microphones
in live applications i s the result ofgreat design and high quality
parts and a consistent assembly technique thats been refined
overforty years. These microphones go through a lot of testing i n
the design phase and conditional
testing throughout their manufacturing life to make sure that
those standards are being kept. Its
Notes Issue #30 - Revisiting the Classics
http://www.shurenotes.com/issue30/a
7/20/2011
7/27/2019 Shure Notes Issue #30 - Revisiting the Classics
3/4
One of the most famous Shuretests is the Drop Test where a
mic is dropped from a certainheight onto a hardwood floorten
times. It can be dinged, it
can be dented, it can bedeformed -- but it still has to
work. Hear Tim and Chris
perform a Drop Test on an SM58by listening to t he Shure
Cast.)
"Theyve been through floods, theyve baked at high temperatures
and frozenat low temperatures, been run over by trucks and
forklifts all manner of
things. They can survive just about anything."
"The smaller size lends itself to getting itinto the right
place, where the SM58
might interfere."
probably worth pointing out that Shure adopted mil-spec
(military specification) te sting proceduresduring WWII when it was
a major supplier to the government of microphones for the milita
ry. Thecompany has maintained those st andards since then and even
applies it t o our studio microphones
today.
Shure microphones have always had tremendous
survivability under very difficult conditions.
We have lots of examples of microphones in ourarchives that are
damaged almost to the point where
you cant recognize them as microphones. And they
still work. Theyve been through floods, theyve bakedat high t
emperatures and frozen at low temperatures,
been run over by trucks and forklifts all manner of
things. They can survive just about anything.
Another aspect of performance is consistencyand since these mics
have been around for somany years now, people are really used
toworking with them. How does consistencycome into play with the
manufacturing of aSM57 or an SM58?Over the course of 40 years, weve
made improvements
in the materials o r in the assembly process but sincethe basic
design hasnt changed, the inherent reliability
from the first models carries through to the ones that
are manufactured today. We have microphones wekeep as shelf
aging units and some are more than 20 or
30 years old. New production models are compared to
them in terms of frequency response and polar pattern
and there has been very little change just a decibel orso in all
that time. In the field, it translates into a high degree of
predictability and familiarityon the part of engineers. Anybody who
has worked in a live sound environment, under the time
constraints and pressures and the unknown factors of weather and
venues and so forth appreciatesa product that continues to be
exactly the same night aft er night, city after city, year after
year.
That brings up another question that comes up all the time.
Whats the realdifference between an SM57 and an SM58? There are
actually a fair number ofmyths and misconceptions about what the
difference really is.The basic difference is the grille. The other
parts -- the diaphragm and voice coil combination,
the magnet, the transformer thats in the handle, the handle
itself, the closi ng ring thatsurrounds the cartridge are
identical.
In the SM58, the ball grille with the foam lining provides an
extra degree of pop protection andwind protection. The SM57 has a
much more compact grille arrangement that doesnt provide
nearly as much protection against blast or wind. But the basic
frequency response and polar
patterns are almost identical there is only a slight difference
in high frequencies where theshape of the grille st arts to affect
the response. But that probably doesnt kick in until 13, 14
or 15 kHz something like that.
Whats the advantage of the SM57 inhaving a smaller head
design?The SM57 is often used as a drum mic - on
snare drums or tom toms for instance - or
an instrument mic for guitar amps.Particularly around drum kits,
the smaller
head of the 57 allows it to fit in among thedrums and other
hardware that make it difficult to get a larger mic in the right
position. Thesmaller size lends i tself to getting it i nto the
right place, where the SM58 might interfere.
From a sound quality standpoint, you wouldnt expect much of a
difference, but you dont need theblast fi lter capability of t he
58 for instrument miking, since you dont have blasts of air coming
off
the drum heads or the guitar amps. Its more of a si ze and
compactness issue that gives it a nod
in that application.
Listen to Tim and Chris compare the SM57 and SM58 for blast
filtering and wind noise here.
The SM58 also provides a measure of pop protection and resists
wind
turbulence. That makes it a better choice for close-up
vocals.
Check out the Shure Cast page for a growing list of
downloadablepodcasts covering a wide spectrum of microphone basics
directionality, frequency response, transducers, stereo miking
techniques along with artist interviews, White Spaces updates
andother helpful pro audio discussions.
Henry Rollins on His Reality: SM58 in the Studio
The interesting thing about me and the SM58 is that I
actually use it in the studio and engineers kind of freak
out. They say, What are you bringing that for? And Illsay Trust
me. Its the only mic Im going to be able t o get my thing going
with.
Notes Issue #30 - Revisiting the Classics
http://www.shurenotes.com/issue30/a
7/20/2011
